As a conventionally available washer-dryer, a drum type washer-dryer is disclosed in JP 2001-113079 A. This drum type washer-dryer includes an outer casing, a water tank placed within the outer casing, a drum rotatably placed within the water tank, and a drying system for drying washing loads contained in the drum.
The drying system has a dehumidifier, a fan unit for sucking in air dehumidified by the dehumidifier, a heating unit for heating air blown out by the fan unit, and a duct for guiding air heated by the this heating unit into the drum.
The fan unit has a fan case, a blower fan rotatably placed within the fan case, a fan motor for driving the blower fan into rotation, and a shaft one end of which is connected to the blower fan and the other end of which is connected to the fan motor. This shaft rotates integrally with the blower fan.
In the drum type washer-dryer of this construction, as the fan unit operates, air in the water tank flows through the dehumidifier, the fan unit and the heating unit in sequence during a drying process. By this process, the air is dehumidified by the dehumidifier with the humidity lowered, and then heated by the heating unit with the temperature increased. This high-temperature, low-humidity air is guided by the duct so as to be blown out into the drum, absorbing the moisture of the washing loads within the drum to increase in its humidity, and thereafter flows again through the dehumidifier, the fan unit and the heating unit in sequence. The washing loads are dried by such a circulation of air.
In this case, waste threads of the washing loads are scattered within the water tank during the drying process. These waste threads pass through the dehumidifier along with air, being deposited on the fan unit. More specifically, the waste threads get entangled with a blower-fan side end portion of the shaft. Then, as the number of times the drying process has been executed increases, the waste threads are deposited inside the fan unit or on the blower-fan side end portion of the shaft. The deposited waste threads cause a narrowing of the air circulation path as well as a resistance to the shaft, thus inhibiting the rotation of the shaft.
As a result, the flow of air in the circulation path is worsened and the rotation of the blower fan becomes insufficient, so that the air for drying the washing loads no longer efficiently circulates. This would lead to a problem of deteriorated drying efficiency of washing loads.
The deterioration of the drying efficiency of washing loads would be a considerable problem when the drum type washer-dryer is used for a long time.